The 4 D’s

The pruning guidelines on this page apply to deciduous trees. Conifers require little or no pruning throughout their lives.

Deciduous trees experience three stages of growth: juvenile, mature, and ancient. The Juvenile period covers approximately the first thirty years of a tree’s life. It is during this period that trees should attain their final form through careful, restrained pruning. The cuts that a tree steward makes on a juvenile tree will determine the shape and character of a tree for the remainder of its life,

Mature trees do not require annual or routine maintenance. A mature tree must not be thinned, limbed up, or “cleaned up”; the shaping was accomplished during the juvenile period.

Mature trees will require attention only in extraordinary circumstances. Most species, if left alone during their maturity, will live for hundreds of years, and some species have natural lifespans in the thousands of years. Mature trees require pruning ONLY in the following circumstances, if they have branches that are:

  • Dead
  • Damaged – dangling or broken
  • Diseased – rotting
  • Disruptive – branches that rub or cross one another; remove the weaker of the two,

Improper care or the hardships of urban existence are responsible for the early decline during the Mature stage of a tree’s life.